Editor’s note: This post was scheduled for last Friday, but something mysterious happened in the technology that we didn’t become aware of right away. Please forgive the delay!

When we expand into outer space, we may contact other sapient species, and it can be guaranteed that they will think differently than us. But we may be able to predict their behavior by their diet. Something that Larry Niven touched on with the carnivorous Kzinti and the herbivorous Puppeteers.

Carnivores: The first thing you should remember is that predators are opportunists, they always take the route that is least expensive. If they get to colonizing other planets I would expect them to have the capability to adapt considering their need for complex ecosystems that would be a hassle to terraform from scratch. Due to their opportunistic natures I doubt that they might go to the trouble of eating other sapient species like us humans, though if there is a massive technological difference they might enslave or domesticate the less advanced species. Relations with humanity would probably be neutral or even allies, we might colonize and terraform dead worlds while they adapt to living ones. However they would likely be very territorial. If we found them as primitives they would probably try eating the explorers, but once that failed would leave them alone unless they managed to communicate, in which case they might end up domesticated (which might make uplifting easier).

Herbivores: To an herbivore, any other animal is a potential enemy, a predator or a competitor. I expect that their planets would be ecological disasters devoid of any other animal species except in the most extreme regions they never got around to colonizing. Since their supporting ecosystems would be comparatively simple they would probably terraform their colonies. Because of that I expect that they would use a lot of weapons of mass destruction in inter-species wars. In addition the fact that extreme paranoia would have been a survival trait in their early history (more than humans anyway) would make diplomacy with them very difficult. If contacted before spaceflight they would inevitably hide or attack, depending on how advanced they were we might have to conquer them or at least quarantine their homeworld, if they haven’t exterminated all their predators yet we might convince them we’re on their side by helping them.

Omnivores: Would probably be closest to humans psychologically, as we are omnivores ourselves. Kind of a wild card, they might terraform, they might adapt, they might exterminate, they might enslave. They might even join forces with us and form the galactic federation, or not. Fortunately (or unfortunately) trends on earth make it seem like most sapient species will be omnivorous.

Plants: I don’t see any reason for plants to become sapient, but maybe a machine civilization would be similar. In short, they wouldn’t care about consumers unless we got in their way. Will definitely be capable of space travel.

Paul, I highly approve of your idea to trace the energy, and look at how diet might affect psychology. But I wonder if you might not be overgeneralizing? Terrestrial carnivores and herbivores span a wide range of behaviors, and all life depends on highly complex ecosystems.

I’m most interested in what you say about plants. Why don’t you think photosynthetic organisms could become sentient? They compete just as hard for resources as any other organism – not eating doesn’t mean they don’t need things. Terrestrial plants are mostly sessile, but I don’t think that’s an universal requirement, either.

And then there are other chemotrophs – organisms that rely neither on eating nor on photosynthesis. But I’m going to save my thoughts on those for my post here next week.

Well civilization requires socialization which narrows the field considerably. As for why photosynthetic organisms wouldn’t be intelligent consider that they don’t need to hunt and that toxins and spines are simpler than legs or other appendages used for locomotion for defending against predators.

I was thinking of sentience rather than civilization, but I see your point.

The energetics are against photosynthetic organisms having sustained locomotion, but what about aquatic or oceanic plants that could swim to better areas? Or a terrestrial plant that stores up energy and jumps once a year to a new location? If a skunk cabbage can store enough energy to heat its flower, jumping seems plausible.

A photosynthetic organism might “want” to move to find more light, or more nutrients, or get away from toxins produced by other species. Escape from herbivores might be too much energetically, though a larger version of the Venus flytrap snapping on a cow’s nose could be very effective.

I’m having more fun with “How could X happen?” than with “X couldn’t happen because.”

Phiala – Sarah Goslee:
“The energetics are against photosynthetic organisms having sustained locomotion, but what about aquatic or oceanic plants that could swim to better areas? Or a terrestrial plant that stores up energy and jumps once a year to a new location? If a skunk cabbage can store enough energy to heat its flower, jumping seems plausible.”

I used to try to imagine all kinds of sophonts: intelligent sea sponges, clams, trees etc. but i could never quite figure out a way that they made biological sense. Here’s the short-cut rule i use now to test the plausibility of a particular type of sophont.

Imagine your species, with approximately human level intelligence. Then imagine a child of that species is born, with an atrophied brain, and is abandoned in the wild once it matures. The degree to which it’s lack of “normal” intelligence is irrelevant to it’s survival, is the degree to which sapiency is implausible in the species. Big, active brains have a high metabolic cost. If the brains don’t “pay their way” it’s hard to imagine a species keeping them. Philosophizing may be a good use of a brain, but philosophy alone doesn’t biologically justify the existence of a brain.

So let’s imagine one of your floating photo-synthesizers, that has leaf-sails, it can trim to sail away from inhospitable waters. It’s metabolism still can only support a narrow (and slow) range of responses to the environment. If all you can do is “turn left”, “turn around”, or “turn right”, even an insect’s set of instinctive responses seems greatly over-engineered.

So the trick to figuring out how it could work is to figure out a niche for a photosythesizer advantageous enough to pay metabolic costs of many actions AND thought. Or actions that are rare and infrequent, but must be calculated precisely.

Vernor Vinge devised some sea plants that had an advantage in spawning if the counted and predicted the complex movements of the tide. But still to reach intelligence they were uplifted, *and* in large part mentally and physically cybernetic– and still an easily confused and somewhat pathetic species. That’s the most plausible plant alien i’ve ever come across.

But as an assist you can imagine these photosynthesizers around a brighter, hotter sun that provides more energy.
Or like the Venus flytrap — make photosynthesis provide only *part* of their diet.

The basic idea seems to me very plausible, that the sort of diet a sophont is designed for would have a big effect on their psychology.

But I doubt generalizing about all herbivores (etc.) as a group would be very useful. Consider some of earth’s most intelligent herbivores: elephants, parrots, and orangutans– and for variety squirrels.

Nearly nothing the elephant meets can threaten it. Most creatures could harm a squirrel- while the parrot and orang fall somewhere in-between. Paranoia seems very plausible as the default response of a sophont that fits in a squirrel-type nitch. But I would expect the same in small creatures whose primary defense is fleeing– no matter what they eat. It seems more connected to their size and/or position in the food chain.

Elephants eat most kinds of plant matter, and tons of it, so it’s easy to imagine intelligent elephant-oids (or goat-oids) eating a planet down to dirt. But creatures more like parrots, orangutans, and squirrels are much more specific in what parts of plants they eat. It doesn’t seem especially likely that sapient versions of these would cause a massive ecological disaster.

Aggression is often thought of as a carnivore’s trait- and while this sometimes makes sense (like when the sophont is modeled on tigers) but plenty of herbivores and omnivores are aggressive too. And many carnivores specialize in eating many small relatively helpless prey. The psychology of a clam-eater is more likely to resemble a root eating herbivore

“…are much more specific in what parts of plants they eat. It doesn’t seem especially likely that sapient versions of these would cause a massive ecological disaster.”

From an almost entirely uneducated stand-point, it does seem a bit more likely that a species with a specialised diet would cause more ecological damage. Assuming that one of a species’ primary goals is to secure a reliable food source, the specialised diet species would seem naturally inclined to eradicate biodiversity in order to reliably mass-produce their food source–their environment will become specialised to produce a very limited number of crops. Species with a more diverse diet would be more tolerant of biodiversity, as they could happily eat more of it. The less biodiverse an environment is, the more fragile they tend to be.

Dylan, I think it depends. A species that specialized on a limited number of crops that can grow in a lot of places would indeed be likely to cause a huge amount of environmental damage — look at the vast swaths of land we’ve planted to monocultures of either wheat, corn, or soy.

But what about a species that prefers the fruit of a tree that only grows on tropical beaches? They might plant their tree on every beach they could find (and perennial agriculture can be much less destructive than animal agriculture), but the rest of the planet would be untouched.

Until they figured out how to build nuclear-powered artificial tropical beach greenhouse environments, anyway. Or were pushed out by more generalist species.

Which is the thing. Earth natural history suggests that it is the generalists who stick around longest. Would a species with a specialised diet survive long enough to become a “civilisation”? Assuming similar planetary conditions such as climate change, roving comets, volcanoes, etc.

That said, there isn’t a narrative in these survivals, only chance, so it’s not like humans as such show any signs of being able to survive particularly well until we’ve done it

I was making a point about the difference between elephants vs parrots a little more specific than generalizations about generalists vs specialists.

Parrots eat fruit — and some other stuff, for simplicity let’s assume our parrot-oids are pure frugivores. Elephants don’t eat wood, but they eat enough leaves and bark to kill a tree– and most other plant life.

As our sapient elephant-oids learns some medical techniques to decrease mortality, their population sky rockets. Earth elephants already have the tendency to destroy ecosystems when their numbers get too high. It’s easy to imaging elephant-oids turning their entire territory into a dust-bowl, where very little survives, because competitor herbivores starved, or where killed to prevent them from eating what the elephant-oids want.

Or frugivore parrot-oids on the other hand would never eat their forests down to a desert. They might weed out non fruit-bearing trees, and exterminate fruit (and parrot) eaters. They would probably irrigate lots of land that was previously prairie to grow more trees, but they (unlike elephant-oids or other broader generalists) will mostly ignore the parts of the world too cold or dry for fruit trees. True there will be less bio-diversity once the parrot-oids have had their way with a planet, but it will probably still have a lot of diversity — there are a lots of kinds of fruit after all, and a lot of animals that are no threat to fruit trees.

Of course i’m talking probabilities. You could think up a scenario where some sort of elephant-oid easily kept their planet an eden, or where parrot-oids turned theirs into a desert.

An extreme specialist would be a special case. Imagine something like a panda that only wants to eat a few species of bamboo. The extent of it’s ecological destruction would be tied to how much of the world is suitable to it’s plant of choice. If the plant only grows under a narrow range of conditions, they probably won’t have much effect on the planet as a whole. Though i don’t think such creatures are good candidates for sapiency. Big brains are less likely to be useful when learning and intelligence are not required to feed yourself.

With respect to irrigation / fruit growing – to go with your example as I have no imagination – agriculture can cause a lot of unrealised damage. If you assume these parrotoids’ population growth mimics ours, they’ll be trying to get as much fruit as they can. Irrigation can concentrate the salts in the soil, causing the resident plant-life to die off and making it unsuitable for a wide swath of plant species. Applying synthetic fertiliser in the wrong quantities under the wrong weather conditions without paying attention to soil condition can result in run-off leading to de-oxygenated water courses. Planting trees actually lowers the groundwater levels, reduces surface water levels (both by take-up and by reducing the amount of water that makes it to the ground) and increases the cloud formation and cover (respiration).

Some of this is lees likely to happen in a permaculture based scenario that you’re putting forward with the parrotoids but size of population can have as many problems as the size of individual. Particularly once we’re up to “global civilisation”. Combine this with how complex a system a planet actually is,and anything can cause an imbalance that might result in a local or global catastrophe.

Clive PONTING’s “A Green History of the World” is a good read for that side of things.

Jo Thomas:
“…Combine this with how complex a system a planet actually is,and anything can cause an imbalance that might result in a local or global catastrophe.”

Maybe.
My point is no that parrot-oids could never offend environmental purists (if they had any), but that the *magnitude* and *probability* of ecological disaster based on their dietary habits is very, very much greater with elephant-oids than parrot-oids.

The probability of a large, grazing species destroying their local environment is high. Pretty much 100%. For sake of ease for silly little Risk Assessment calculations, we’ll make that a score of 10.

However the actual damage they cause will remain low as, generally, they have seasonal movements / migrations that allow over-grazed areas to recover. This is true even within relatively territorial species and true as long as we don’t fence them in. Its unlikely there’ll be a huge amount of long-term damage because grazing damage – if the animals are allowed to migrate – is usually never more than one growing season’s worth of trouble. So, let’s say on a hazard scale of 1 to 5 with 5 being a dinosaur extinction type event, we’re looking at a 1.

However, such local wipe-outs must decrease the chance of ever becoming a high-tech civilisation – under the assumption that at least some part of the population must settle in order to mine and quarry to supply the materials needed to say, build space-worthy vehicles. It’s also unlikely that an elephant as the species currently are would have the drive to want to, say, build a faster rocket. Therefore, large herbivores are more likely to stay a nomadic, low-tech species with many, small scale ecological disasters. I think we just found our “noble savage” stereotype.

For what it’s worth, (Earth) nature is pretty much primed for this sort of behaviour. For example, most woodlands do better with small, regular forest fires to clear away dry, dead wood. Slash and burn has little long-term affect and allows marginal species associated with grassland and scrub to break through the trees (this is all part of natural habitat progression).

On the other hand, when some form of single species or single habitat is forced into dominance. If old, dry wood is left lying around for several seasons, then chances are there’ll be a very hot day starting off a fire that takes out a huge swathe – possibly including homes and business. Or if all the woodlands are cleared from a hillside you might have flash floods and mud / land slides. Or if all the marshlands are drained and built on, you might have river and tidal floods. You get the idea. The thing is, these are not issues associated with nomadic behaviour but with settled behaviour – and with a level of technology where you start engineering the world around you. Sometimes it works, sometimes it doesn’t. My point with this is that the mentality we’re associating with the parrot(oid)s is of a species that starts to control its environment fairly early on.

They get in the habit of pulling up the seedlings of the wrong trees when they become sophonts. This will be low risk, probably not even showing up as a 10 on the silly little Risk Assessment above. We can discuss the value of biodiversity another time. Success increases the global population of our enterprising heroes and the civilisation expands.

So they try their hand (wing? claw?) at irrigation projects – possibly their first engineering project is to get their favourite orchard to spread out. It works or it doesn’t. They keep trying. Positive feedback from the habitat (the trees succeeding) encourages more and bigger projects. Somewhere about here, we’re getting to the stage where they can do local wipe-outs, too. Depending on what they’re up to, they’re more likely to have a long-term effect than the elephants because they’re making long-term decisions / uses of the resources in the area. But it won’t be more than a level 2 hazard for the globe and the probability of it happening (at this stage) is somewhat lower, say 50% (5) so it comes out with the same risk score (10).

However, manipulation of one’s surroundings can have issues, as already mentioned and the bigger their projects get, the bigger the negative feedback will be if it goes wrong. Truly going global with these things is highly improbable but it is possible and the hazard from a world war or a pandemic or a shortage of food – all of which have a human element, without getting into “environmental purists” territory – doesn’t really bear thinking about.

But you are overlooking the fact that elephants aren’t merely grass-eaters like cattle. A hungry elephant will tear down an entire tree to get to the leaves a the top or to eat the bark. Their appetite isn’t limited to stuff that naturally grows back in a season.

As far as nomadism, i agree that elephants– and similar large creatures that generally have to travel a lot to eat– don’t have the best chance to develop a complex machine technology. But the point of the exercise in the original post is to see what we can infer about a sapient species we might meet in space, based on knowing it’s diet.

And the devastation i’m predicting for the elephant-oids is more than what real elephants accomplish today. It’s what they could do armed with knowledge and and (for instance) high medieval tech.

For much of history a lot of humanity was nomadic, not only low tech bushmen, but the Kelts and the Huns, etc. Nomadism is an easy choice when populations are low and food is abundant. But intelligent creatures will be better at avoiding dangers, so populations will increase. With greater competition for the best food spots, and the accumulation of the nifty possessions that technology allows, even some elephant-oids (especially if they are destined for space) will start to settle down in the best food spots — and like humans develop the technology and social organization that allows them to defend the territory from their still-nomaic brethren. And like humans, these city elephant-oids will probably turn to agriculture to help support their growing numbers.

Or if you don’t buy that scenario: small communities of tool-making elephant-oids could form in spots not rich enough to support them. But by being stationary, they could have workshops to make tools to trade for food with the local nomads.

Either way they could get some of their numbers to live in one place, which is so helpful in developing a material technology. So they learn to make fire and walls, scythes and spears, and medicine.

Actually i’m having more fun spinning this scenario than making my original point. I’ll wrap it up.

Anyway, at some point the sedentary elephants are going to start building walls, moats, mine-fields, or armored soldiers– whatever to close off land the nomads were used to accessing, especially when their food supply is becoming insufficient. Driven by desperation, this large population of nomads who have already eaten everything they wanted to eat go back and eat everything else and kill the herbivores competing for the last leaf. These starving, tech-using elephant-oids are much more effective at scrounging up the last bit of vegetation from the land than their Terran namesakes. Not only the grass, but the forests are consumed, and remotely edible roots are pulled up. Left in their wake is a landscape of dirt or mud. And erosion, mudslides, and desertification, and mass extinctions.

How about aliens who consume electricity? There’s a new race of aliens evolving all around us today. Doubling their capabilites every eighteen months: it won’t be long before our laptops are smarter than we are.

Our first alien encounter will probably be with electricity eaters. Our explorers all live on electricity. Robots are faster and cheaper than men … and they don’t demand a round-trip ticket. Wouldn’t other civilization’s scouts be the same?